474 lines
12 KiB
C
474 lines
12 KiB
C
/*
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* Nano River Technologies viperboard i2c master driver
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*
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* (C) 2012 by Lemonage GmbH
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* Author: Lars Poeschel <poeschel@lemonage.de>
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* All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#include <linux/mutex.h>
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#include <linux/platform_device.h>
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#include <linux/usb.h>
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#include <linux/i2c.h>
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#include <linux/mfd/viperboard.h>
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struct vprbrd_i2c {
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struct i2c_adapter i2c;
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u8 bus_freq_param;
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};
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/* i2c bus frequency module parameter */
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static u8 i2c_bus_param;
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static unsigned int i2c_bus_freq = 100;
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module_param(i2c_bus_freq, int, 0);
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MODULE_PARM_DESC(i2c_bus_freq,
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"i2c bus frequency in khz (default is 100) valid values: 10, 100, 200, 400, 1000, 3000, 6000");
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static int vprbrd_i2c_status(struct i2c_adapter *i2c,
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struct vprbrd_i2c_status *status, bool prev_error)
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{
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u16 bytes_xfer;
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int ret;
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struct vprbrd *vb = (struct vprbrd *)i2c->algo_data;
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/* check for protocol error */
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bytes_xfer = sizeof(struct vprbrd_i2c_status);
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ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
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VPRBRD_USB_REQUEST_I2C, VPRBRD_USB_TYPE_IN, 0x0000, 0x0000,
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status, bytes_xfer, VPRBRD_USB_TIMEOUT_MS);
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if (ret != bytes_xfer)
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prev_error = true;
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if (prev_error) {
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dev_err(&i2c->dev, "failure in usb communication\n");
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return -EREMOTEIO;
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}
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dev_dbg(&i2c->dev, " status = %d\n", status->status);
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if (status->status != 0x00) {
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dev_err(&i2c->dev, "failure: i2c protocol error\n");
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return -EPROTO;
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}
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return 0;
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}
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static int vprbrd_i2c_receive(struct usb_device *usb_dev,
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struct vprbrd_i2c_read_msg *rmsg, int bytes_xfer)
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{
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int ret, bytes_actual;
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int error = 0;
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/* send the read request */
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ret = usb_bulk_msg(usb_dev,
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usb_sndbulkpipe(usb_dev, VPRBRD_EP_OUT), rmsg,
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sizeof(struct vprbrd_i2c_read_hdr), &bytes_actual,
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VPRBRD_USB_TIMEOUT_MS);
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if ((ret < 0)
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|| (bytes_actual != sizeof(struct vprbrd_i2c_read_hdr))) {
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dev_err(&usb_dev->dev, "failure transmitting usb\n");
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error = -EREMOTEIO;
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}
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/* read the actual data */
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ret = usb_bulk_msg(usb_dev,
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usb_rcvbulkpipe(usb_dev, VPRBRD_EP_IN), rmsg,
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bytes_xfer, &bytes_actual, VPRBRD_USB_TIMEOUT_MS);
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if ((ret < 0) || (bytes_xfer != bytes_actual)) {
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dev_err(&usb_dev->dev, "failure receiving usb\n");
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error = -EREMOTEIO;
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}
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return error;
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}
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static int vprbrd_i2c_addr(struct usb_device *usb_dev,
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struct vprbrd_i2c_addr_msg *amsg)
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{
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int ret, bytes_actual;
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ret = usb_bulk_msg(usb_dev,
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usb_sndbulkpipe(usb_dev, VPRBRD_EP_OUT), amsg,
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sizeof(struct vprbrd_i2c_addr_msg), &bytes_actual,
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VPRBRD_USB_TIMEOUT_MS);
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if ((ret < 0) ||
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(sizeof(struct vprbrd_i2c_addr_msg) != bytes_actual)) {
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dev_err(&usb_dev->dev, "failure transmitting usb\n");
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return -EREMOTEIO;
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}
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return 0;
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}
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static int vprbrd_i2c_read(struct vprbrd *vb, struct i2c_msg *msg)
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{
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int ret;
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u16 remain_len, len1, len2, start = 0x0000;
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struct vprbrd_i2c_read_msg *rmsg =
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(struct vprbrd_i2c_read_msg *)vb->buf;
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remain_len = msg->len;
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rmsg->header.cmd = VPRBRD_I2C_CMD_READ;
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while (remain_len > 0) {
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rmsg->header.addr = cpu_to_le16(start + 0x4000);
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if (remain_len <= 255) {
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len1 = remain_len;
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len2 = 0x00;
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rmsg->header.len0 = remain_len;
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rmsg->header.len1 = 0x00;
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rmsg->header.len2 = 0x00;
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rmsg->header.len3 = 0x00;
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rmsg->header.len4 = 0x00;
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rmsg->header.len5 = 0x00;
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remain_len = 0;
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} else if (remain_len <= 510) {
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len1 = remain_len;
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len2 = 0x00;
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rmsg->header.len0 = remain_len - 255;
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rmsg->header.len1 = 0xff;
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rmsg->header.len2 = 0x00;
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rmsg->header.len3 = 0x00;
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rmsg->header.len4 = 0x00;
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rmsg->header.len5 = 0x00;
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remain_len = 0;
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} else if (remain_len <= 512) {
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len1 = remain_len;
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len2 = 0x00;
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rmsg->header.len0 = remain_len - 510;
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rmsg->header.len1 = 0xff;
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rmsg->header.len2 = 0xff;
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rmsg->header.len3 = 0x00;
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rmsg->header.len4 = 0x00;
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rmsg->header.len5 = 0x00;
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remain_len = 0;
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} else if (remain_len <= 767) {
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len1 = 512;
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len2 = remain_len - 512;
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rmsg->header.len0 = 0x02;
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rmsg->header.len1 = 0xff;
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rmsg->header.len2 = 0xff;
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rmsg->header.len3 = remain_len - 512;
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rmsg->header.len4 = 0x00;
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rmsg->header.len5 = 0x00;
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remain_len = 0;
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} else if (remain_len <= 1022) {
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len1 = 512;
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len2 = remain_len - 512;
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rmsg->header.len0 = 0x02;
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rmsg->header.len1 = 0xff;
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rmsg->header.len2 = 0xff;
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rmsg->header.len3 = remain_len - 767;
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rmsg->header.len4 = 0xff;
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rmsg->header.len5 = 0x00;
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remain_len = 0;
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} else if (remain_len <= 1024) {
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len1 = 512;
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len2 = remain_len - 512;
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rmsg->header.len0 = 0x02;
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rmsg->header.len1 = 0xff;
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rmsg->header.len2 = 0xff;
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rmsg->header.len3 = remain_len - 1022;
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rmsg->header.len4 = 0xff;
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rmsg->header.len5 = 0xff;
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remain_len = 0;
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} else {
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len1 = 512;
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len2 = 512;
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rmsg->header.len0 = 0x02;
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rmsg->header.len1 = 0xff;
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rmsg->header.len2 = 0xff;
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rmsg->header.len3 = 0x02;
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rmsg->header.len4 = 0xff;
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rmsg->header.len5 = 0xff;
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remain_len -= 1024;
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start += 1024;
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}
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rmsg->header.tf1 = cpu_to_le16(len1);
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rmsg->header.tf2 = cpu_to_le16(len2);
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/* first read transfer */
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ret = vprbrd_i2c_receive(vb->usb_dev, rmsg, len1);
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if (ret < 0)
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return ret;
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/* copy the received data */
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memcpy(msg->buf + start, rmsg, len1);
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/* second read transfer if neccessary */
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if (len2 > 0) {
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ret = vprbrd_i2c_receive(vb->usb_dev, rmsg, len2);
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if (ret < 0)
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return ret;
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/* copy the received data */
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memcpy(msg->buf + start + 512, rmsg, len2);
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}
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}
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return 0;
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}
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static int vprbrd_i2c_write(struct vprbrd *vb, struct i2c_msg *msg)
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{
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int ret, bytes_actual;
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u16 remain_len, bytes_xfer,
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start = 0x0000;
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struct vprbrd_i2c_write_msg *wmsg =
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(struct vprbrd_i2c_write_msg *)vb->buf;
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remain_len = msg->len;
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wmsg->header.cmd = VPRBRD_I2C_CMD_WRITE;
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wmsg->header.last = 0x00;
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wmsg->header.chan = 0x00;
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wmsg->header.spi = 0x0000;
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while (remain_len > 0) {
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wmsg->header.addr = cpu_to_le16(start + 0x4000);
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if (remain_len > 503) {
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wmsg->header.len1 = 0xff;
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wmsg->header.len2 = 0xf8;
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remain_len -= 503;
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bytes_xfer = 503 + sizeof(struct vprbrd_i2c_write_hdr);
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start += 503;
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} else if (remain_len > 255) {
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wmsg->header.len1 = 0xff;
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wmsg->header.len2 = (remain_len - 255);
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bytes_xfer = remain_len +
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sizeof(struct vprbrd_i2c_write_hdr);
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remain_len = 0;
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} else {
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wmsg->header.len1 = remain_len;
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wmsg->header.len2 = 0x00;
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bytes_xfer = remain_len +
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sizeof(struct vprbrd_i2c_write_hdr);
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remain_len = 0;
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}
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memcpy(wmsg->data, msg->buf + start,
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bytes_xfer - sizeof(struct vprbrd_i2c_write_hdr));
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ret = usb_bulk_msg(vb->usb_dev,
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usb_sndbulkpipe(vb->usb_dev,
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VPRBRD_EP_OUT), wmsg,
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bytes_xfer, &bytes_actual, VPRBRD_USB_TIMEOUT_MS);
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if ((ret < 0) || (bytes_xfer != bytes_actual))
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return -EREMOTEIO;
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}
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return 0;
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}
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static int vprbrd_i2c_xfer(struct i2c_adapter *i2c, struct i2c_msg *msgs,
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int num)
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{
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struct i2c_msg *pmsg;
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int i, ret,
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error = 0;
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struct vprbrd *vb = (struct vprbrd *)i2c->algo_data;
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struct vprbrd_i2c_addr_msg *amsg =
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(struct vprbrd_i2c_addr_msg *)vb->buf;
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struct vprbrd_i2c_status *smsg = (struct vprbrd_i2c_status *)vb->buf;
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dev_dbg(&i2c->dev, "master xfer %d messages:\n", num);
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for (i = 0 ; i < num ; i++) {
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pmsg = &msgs[i];
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dev_dbg(&i2c->dev,
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" %d: %s (flags %d) %d bytes to 0x%02x\n",
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i, pmsg->flags & I2C_M_RD ? "read" : "write",
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pmsg->flags, pmsg->len, pmsg->addr);
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mutex_lock(&vb->lock);
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/* directly send the message */
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if (pmsg->flags & I2C_M_RD) {
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/* read data */
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amsg->cmd = VPRBRD_I2C_CMD_ADDR;
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amsg->unknown2 = 0x00;
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amsg->unknown3 = 0x00;
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amsg->addr = pmsg->addr;
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amsg->unknown1 = 0x01;
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amsg->len = cpu_to_le16(pmsg->len);
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/* send the addr and len, we're interested to board */
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ret = vprbrd_i2c_addr(vb->usb_dev, amsg);
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if (ret < 0)
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error = ret;
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ret = vprbrd_i2c_read(vb, pmsg);
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if (ret < 0)
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error = ret;
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ret = vprbrd_i2c_status(i2c, smsg, error);
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if (ret < 0)
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error = ret;
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/* in case of protocol error, return the error */
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if (error < 0)
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goto error;
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} else {
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/* write data */
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ret = vprbrd_i2c_write(vb, pmsg);
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amsg->cmd = VPRBRD_I2C_CMD_ADDR;
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amsg->unknown2 = 0x00;
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amsg->unknown3 = 0x00;
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amsg->addr = pmsg->addr;
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amsg->unknown1 = 0x00;
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amsg->len = cpu_to_le16(pmsg->len);
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/* send the addr, the data goes to to board */
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ret = vprbrd_i2c_addr(vb->usb_dev, amsg);
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if (ret < 0)
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error = ret;
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ret = vprbrd_i2c_status(i2c, smsg, error);
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if (ret < 0)
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error = ret;
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if (error < 0)
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goto error;
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}
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mutex_unlock(&vb->lock);
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}
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return 0;
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error:
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mutex_unlock(&vb->lock);
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return error;
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}
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static u32 vprbrd_i2c_func(struct i2c_adapter *i2c)
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{
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return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
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}
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/* This is the actual algorithm we define */
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static const struct i2c_algorithm vprbrd_algorithm = {
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.master_xfer = vprbrd_i2c_xfer,
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.functionality = vprbrd_i2c_func,
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};
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static const struct i2c_adapter_quirks vprbrd_quirks = {
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.max_read_len = 2048,
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.max_write_len = 2048,
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};
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static int vprbrd_i2c_probe(struct platform_device *pdev)
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{
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struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
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struct vprbrd_i2c *vb_i2c;
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int ret;
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int pipe;
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vb_i2c = devm_kzalloc(&pdev->dev, sizeof(*vb_i2c), GFP_KERNEL);
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if (vb_i2c == NULL)
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return -ENOMEM;
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/* setup i2c adapter description */
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vb_i2c->i2c.owner = THIS_MODULE;
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vb_i2c->i2c.class = I2C_CLASS_HWMON;
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vb_i2c->i2c.algo = &vprbrd_algorithm;
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vb_i2c->i2c.quirks = &vprbrd_quirks;
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vb_i2c->i2c.algo_data = vb;
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/* save the param in usb capabable memory */
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vb_i2c->bus_freq_param = i2c_bus_param;
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snprintf(vb_i2c->i2c.name, sizeof(vb_i2c->i2c.name),
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"viperboard at bus %03d device %03d",
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vb->usb_dev->bus->busnum, vb->usb_dev->devnum);
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/* setting the bus frequency */
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if ((i2c_bus_param <= VPRBRD_I2C_FREQ_10KHZ)
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&& (i2c_bus_param >= VPRBRD_I2C_FREQ_6MHZ)) {
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pipe = usb_sndctrlpipe(vb->usb_dev, 0);
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ret = usb_control_msg(vb->usb_dev, pipe,
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VPRBRD_USB_REQUEST_I2C_FREQ, VPRBRD_USB_TYPE_OUT,
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0x0000, 0x0000, &vb_i2c->bus_freq_param, 1,
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VPRBRD_USB_TIMEOUT_MS);
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if (ret != 1) {
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dev_err(&pdev->dev, "failure setting i2c_bus_freq to %d\n",
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i2c_bus_freq);
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return -EIO;
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}
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} else {
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dev_err(&pdev->dev,
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"invalid i2c_bus_freq setting:%d\n", i2c_bus_freq);
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return -EIO;
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}
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vb_i2c->i2c.dev.parent = &pdev->dev;
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/* attach to i2c layer */
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i2c_add_adapter(&vb_i2c->i2c);
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platform_set_drvdata(pdev, vb_i2c);
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return 0;
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}
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static int vprbrd_i2c_remove(struct platform_device *pdev)
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{
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struct vprbrd_i2c *vb_i2c = platform_get_drvdata(pdev);
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i2c_del_adapter(&vb_i2c->i2c);
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return 0;
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}
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static struct platform_driver vprbrd_i2c_driver = {
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.driver.name = "viperboard-i2c",
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.driver.owner = THIS_MODULE,
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.probe = vprbrd_i2c_probe,
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.remove = vprbrd_i2c_remove,
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};
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static int __init vprbrd_i2c_init(void)
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{
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switch (i2c_bus_freq) {
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case 6000:
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i2c_bus_param = VPRBRD_I2C_FREQ_6MHZ;
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break;
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case 3000:
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i2c_bus_param = VPRBRD_I2C_FREQ_3MHZ;
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break;
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case 1000:
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i2c_bus_param = VPRBRD_I2C_FREQ_1MHZ;
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break;
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case 400:
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i2c_bus_param = VPRBRD_I2C_FREQ_400KHZ;
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break;
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case 200:
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i2c_bus_param = VPRBRD_I2C_FREQ_200KHZ;
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break;
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case 100:
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i2c_bus_param = VPRBRD_I2C_FREQ_100KHZ;
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break;
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case 10:
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i2c_bus_param = VPRBRD_I2C_FREQ_10KHZ;
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break;
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default:
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pr_warn("invalid i2c_bus_freq (%d)\n", i2c_bus_freq);
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i2c_bus_param = VPRBRD_I2C_FREQ_100KHZ;
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}
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return platform_driver_register(&vprbrd_i2c_driver);
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}
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subsys_initcall(vprbrd_i2c_init);
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|
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static void __exit vprbrd_i2c_exit(void)
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|
{
|
|
platform_driver_unregister(&vprbrd_i2c_driver);
|
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}
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module_exit(vprbrd_i2c_exit);
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|
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MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
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|
MODULE_DESCRIPTION("I2C master driver for Nano River Techs Viperboard");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("platform:viperboard-i2c");
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